Crank arm



FIG. 1 is a perspective view of the crank arm;

FIG. 2 is another perspective view of the crank arm;

FIG. 3 is a left side view of the crank arm;

FIG. 4 is a right side view of the crank arm;

FIG. 5 is a rear view of the crank arm;

FIG. 6 is a front view of the crank arm;

FIG. 7 is a top view of the crank arm; and,

FIG. 8 is a bottom view of the crank arm.

The broken line portions of the crank arm and the broken line environmental structure form no part of the claimed design. 

The ornamental design for a crank arm, as shown and described. 